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Gdańsk University of Technology

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Publications from the year 2024

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  • How to make membrane distillation greener? A review on environmentally friendly and sustainable aspects
    • Emilia Gontarek-Castro
    • Roberto Castro Munoz
    2024 GREEN CHEMISTRY

    There is an urgent need for the development of new water resources in order to solve the problem of the world’s growing demand for clean water. Membrane distillation (MD) is a promising alternative to conventional seawater desalination. Although MD itself is often defined as sustainable desalination technology, there are many aspects within the membrane manufacture and process operation that make it far from being green. For instance, non-biodegradable polymers, toxic solvents and fluoroalkyl silanes are typical chemicals that unfortunately are used in membrane fabrication protocols. Additionally, the huge amount of wastewater generated from membrane fabrication processes makes solvent-free methods more attractive and desired for extensive investigation. Apart from this, the low energy efficiency of MD process can be effectively overcome by integrating the MD systems with low-grade waste heat. This review critically addresses and discusses the recent advances in methods and strategies to improve the sustainability of MD technology, which is not a common scope of study among the research community. Here, our attention has been devoted to main aspects in MD membrane fabrication, such as polymers, solvents (and its costs), nonsolvents, additives, solvent-free fabrication procedures, fluoro-free post modification, and MD operation (energy consumption). This review intends to introduce inspiration for membrane scientists for the development of the next-generation MD process, by promoting the sustainable transformation of today’s approaches into a greener way. In this latter scenario, we provide some punctual considerations that could be followed by the researchers in the field.

  • Human carnosinases: A brief history, medicinal relevance, and in silico analyses
    • Klaudia Chmielewska
    • Serena Vittorio
    • Silva Gervasoni
    • Krystyna Dzierzbicka
    • Iwona Inkielewicz-Stępniak
    • Giulio Vistoli
    2024 Full text DRUG DISCOVERY TODAY

    Carnosine, an endogenous dipeptide, has been found to have a plethora of medicinal properties, such as antioxidant, antiageing, and chelating effects, but with one downside: a short half-life. Carnosinases and two hydrolytic enzymes, which remain enigmatic, are responsible for these features. Hence, here we emphasize why research is valuable for better understanding crucial concepts like ageing, neurodegradation, and cancerogenesis, given that inhibition of carnosinases might significantly prolong carnosine bioavailability and allow its further use in medicine. Herein, we explore the literature regarding carnosinases and present a short in silico analysis aimed at elucidating the possible recognition pattern between CN1 and its ligands.

  • Hyaluronic acid/tannic acid films for wound healing application
    • Marcin Wekwejt
    • Marcin Małek
    • Anna Ronowska
    • Anna Michno
    • Anna Pałubicka
    • Agnieszka Klimek
    • Beata Kaczmarek-Szczepańska
    2024 Full text INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES

    In this study, thin films based on hyaluronic acid (HA) with tannic acid (TA) were investigated in three different weight ratios (80HA/20TA, 50HA/50TA, 20HA/80TA) for their application as materials for wound healing. Surface free energy, as well as their roughness, mechanical properties, water vapor permeability rate, and antioxidant activity were determined. Moreover, their compatibility with blood and osteoblast cells was investigated. The irritation effect caused by hyaluronic acid/tannic acid films was also considered with the use of are constructed human epidermis model. The irritation effect for hyaluronic acid/tannic acid films by the in vitro method was also studied. The low surface free energy, surface roughness, and antioxidant activity presented by the obtained films were examined. All the tested compositions of hyaluronic acid/tannic acid films were hemocompatible, but only films based on 50HA/50TA were fully cytocompatible. Regarding the potential implantation, all the films except 80HA/20TA showed appropriate mechanical properties. The specimens did not exert the irritation effect during the studies involving reconstructed human epidermis.

  • Hybrid geothermal-fossil power cycle analysis in a Polish setting with a focus on off-design performance and CO2 emissions reductions
    • Kacper Szturgulewski
    • Jerzy Głuch
    • Marta Drosińska-Komor
    • Paweł Ziółkowski
    • Andrzej Gardzilewicz
    • Katarzyna Brzezińska-gołębiewska
    2024 ENERGY

    Growing demand for electricity due to economic development contributes to increased greenhouse gas production, especially CO2. However, emissions can be limited by enhancing the efficiency of primary energy conversion, such as integrating geothermal energy into coal-fired power plants. Therefore, this paper proposes replacing conventional feed-water heaters with geothermal preheaters to create a hybridized system. This study was based on a numerical model validated at a selected Polish power unit. The model was subsequently calibrated for off-design conditions to facilitate partial load analysis. The obtained characteristics outperformed those of the non-hybrid unit, generating over 18 MW of electric power output. Such an improvement could potentially boost the unit’s net efficiency by more than 2.6%. This enhancement is significant as power units typically operate under part load for approximately 90% of the time, hence the need to evaluate the performance characteristics of hybridized units in those states. Furthermore, the research outlines the potential decrease in the plant’s CO2 emission factor, with reductions reaching up to 6.5% under off-design conditions. Based on a gap analysis of the existing literature, this paper’s comprehensive partial load evaluation serves as a new addition to research on hybridized systems.

  • Hybrid Laboratory of Radio Communication With Online Simulators and Remote Access
    • Jarosław Sadowski
    • Jacek Stefański
    2024 IEEE Transactions on Education

    Contribution: Two toolsets for the remote teaching of radio communication laboratory classes: 1) online simulators for individual work of students and 2) a remote access system to laboratory workstations for group work. Initial assumptions and method of implementation of both tools are presented. Background: The COVID-19 pandemic has forced a change in teaching at all levels of education. The specificity of practical classes, such as laboratories, means that the tools used must often be atypical, prepared for a specific type of activity. Intended Outcomes: Hybrid laboratory with tools for remote learning in the form of online simulators and remote access to laboratory workstations, enabling students to achieve the same educational results in the field of radiocommunication as presential classes. Application Design: Online simulators were prepared as Javascript code run in a Web browser as part of a html page, which provide easy integration with various learning platforms and Web servers. The remote access system uses Javascript code for the user interface and a gateway server based on an Apache Web server and FastCGI interface to communicate with C/C++ programs responsible for controlling measuring equipment. Findings: Online simulators have been positively assessed by students during two years of remote learning, but comparison of the grades from remote and presential classes is inconclusive. The obtained grades were comparable in the first year of remote laboratories, but they were worse in the second year than the grades from classroom learning. The system for remote access to the laboratory stands has not yet been evaluated.

  • Hybrid use of the building as a method supporting epidemic safety
    • Rafał Janowicz
    • Wacław Szarejko
    • Marta Koperska-Kośmicka
    • Agnieszka Gębczyńska-Janowicz
    2024 Full text MEDYCYNA PRACY

    The COVID-19 pandemic has resulted in changing organisational and technical requirements in the operation of treatment facilities. This paper summarises the available knowledge on the principles of hybrid design of the architecture of treatment units to ensure that different levels of sanitary and hygienic safeguards can be implemented. The basis of this narrative overview is an analysis of the existing Polish legislation on required personnel protection measures and the European Commission’s recommendations for the long-term optimisation of building operating costs. In addition, due to the multifaceted and complex nature of the issue, the review was extended to include an example of practice in the technical adaptation of medical buildings for hybrid use in the event of a pan- demic of an aetiological agent of risk category III, as a confirmation of the postulate regarding the need to modify the guidelines for the architectural design of the space of medical units, particularly those involved in the care of the elderly.

  • Hybridized PWM Strategy for Three- and Multiphase Three-Level NPC Inverters
    • Arkadiusz Lewicki
    • Dmytro Kondratenko
    • Charles Odeh
    2024 Full text IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS

    A simple hybridized pulsewidth modulation (PWM) algorithm for three- and multiphase three-level neutral point clamped (NPC) inverters is proposed. The proposed solution is based on classical space vector PWM (SVPWM) algorithms for two-level inverters but can also be based on sinusoidal PWM with min–max injection. An additional level of output voltage is obtained by modifying the resulting switching patterns taking into account the actual dc-link voltages. In the case of SVPWM algorithms, such an approach eliminates the need to find the subsector where the reference voltage vector is located. It is also not necessary to analyze the changes in the position and length of active vectors in the case of dc-link voltage imbalance. DC-link voltage balancing is achieved by modifying the switching pattern, taking into account the values and direction of phase currents and actual dc-link voltages. Also, the algorithm optimizes the switching pattern and eliminates unnecessary switching instances. The proposed approach utilizes both space vector analysis and independent control of individual inverter-legs. The latter is peculiar to carrier-based PWM; hence, the proposed solution is termed hybridized PWM. Presented experimental tests and results validated the proposed control concept and algorithm for three- and multiphase NPC inverters

  • Hydration of N-Hydroxyurea from Ab Initio Molecular Dynamics Simulations
    • Mateusz Balicki
    • Maciej Śmiechowski
    2024 Full text MOLECULES

    N-Hydroxyurea (HU) is an important chemotherapeutic agent used as a first-line treatment in conditions such as sickle cell disease and β-thalassemia, among others. To date, its properties as a hydrated molecule in the blood plasma or cytoplasm are dramatically understudied, although they may be crucial to the binding of HU to the radical catalytic site of ribonucleotide reductase, its molecular target. The purpose of this work is the comprehensive exploration of HU hydration. The topic is studied using AIMD simulations that apply a first principles representation of the electron density of the system. This allows for the calculation of infrared spectra, which may be decomposed spatially to better capture the signatures of solute–solvent interactions. The studied molecule is found to be strongly hydrated and tightly bound to the first shell water molecules. The analysis of the distance-dependent spectra of HU shows that the E and Z conformers spectrally affect 3.4 and 2.5 of the closest H2O molecules, in spheres of radii of 3.7 Å and 3.5 Å, respectively. The distance-dependent spectra corresponding to these cutoff radii show increased absorbance in the red-shifted part of the water OH stretching vibration band, indicating local enhancement of the hydrogen bond network. The radially resolved IR spectra also demonstrate that HU effortlessly incorporates into the hydrogen bond network of water and has an enhancing effect on this network. Metadynamics simulations based on AIMD methodology provide a picture of the conformational equilibria of HU in solution. Contrary to previous investigations of an isolated HU molecule in the gas phase, the Z conformer of HU is found here to be more stable by 17.4 kJ·mol−1 than the E conformer, pointing at the crucial role that hydration plays in determining the conformational stability of solutes. The potential energy surface for the OH group rotation in HU indicates that there is no intramolecular hydrogen bond in Z-HU in water, in stark contrast to the isolated solute in the gas phase. Instead, the preferred orientation of the hydroxyl group is perpendicular to the molecular plane of the solute. In view of the known chaotropic effect of urea and its N-alkyl-substituted derivatives, HU emerges as a unique urea derivative that exhibits a kosmotropic ordering of nearby water. This property may be of crucial importance for its binding to the catalytic site of ribonucleotide reductase with a displacement of a water molecule.

  • Hydrochars as a bio-based adsorbent for heavy metals removal: A review of production processes, adsorption mechanisms, kinetic models, regeneration and reusability of hydrochar
    • Aisha Khanzada
    • Hussein Al-Hazmi
    • Tonni Agustiono Kurniawan
    • Joanna Majtacz
    • Grzegorz Piechota
    • Gopalakrishnan Kumar
    • Peyman Ezzati
    • Mohammad Saeb
    • Navid Rabiee
    • Hassan Karimi-Maleh
    • Eder C. Lima
    • Jacek Mąkinia
    2024 SCIENCE OF THE TOTAL ENVIRONMENT

    The spread of heavy metals throughout the ecosystem has extremely endangered human health, animals, plants, and natural resources. Hydrochar has emerged as a promising adsorbent for removing heavy metals from water and wastewater. Hydrochar, obtained from hydrothermal carbonization of biomass, owns unique physical and chemical properties that are highly potent in capturing heavy metals via surface complexation, electrostatic interactions, and ion exchange mechanisms. This review focuses on removing heavy metals by hydrochar adsorbents from water bodies. The article discusses factors affecting the adsorption capacity of hydrochars, such as contact time, pH, initial metal concentration, temperature, and competing ions. Literature on optimization approaches such as surface modification, composite development, and hybrid systems are reviewed to enlighten mechanisms undertaking the efficiency of hydrochars in heavy metals removal from wastewater. The review also addresses challenges such as hydrochar regeneration and reusability, alongside potential issues related to its disposal and metal leaching. Integration with current water purification methods and the significance of ongoing research and initiatives promoting hydrochar-based technologies were also outlined. The article concludes that combining hydrochar with modern technologies such as nanotechnology and advanced oxidation techniques holds promise for improving heavy metal remediation. Overall, this comprehensive analysis provides valuable insights to guide future studies and foster the development of effective, affordable, and environmentally friendly heavy metal removal technologies to ensure the attainment of safer drinking water for communities worldwide.

  • Hydrogen and chalcogen bonds in crystals of chalcogenadiazolecarboxylic acids – competition or cooperation?
    • Jan Alfuth
    • Agnieszka Czapik
    • Beata Zadykowicz
    • Teresa Olszewska
    2024 CRYSTENGCOMM

    This article presents crystal structures of chalcogenadiazolecarboxylic acids bearing both a hydrogen and a chalcogen bond donor. The selected molecules varied in the size of the aromatic unit, the chalcogen atom and/or the position of the carboxyl group in the core structure. The most common synthons in their lattice are "R" _"2" ^"2" (8) self-complementary acid dimers or four-membered [Ch···N]2 rings. Supramolecular synthons where chalcogenadiazole moieties interact with the carboxyl group were also identified. Both ESP calculations and experimental data showed that all the studied molecules adopted flat conformations, but only in the case of three crystal structures were flat sheets observed. To assess the contribution of hydrogen and chalcogen bonds to the stabilization of the crystal structure, crystal lattice energy calculations were performed.

  • Hydrogen direct reduction and reoxidation behaviour of high-grade pellets
    • Pasquale Cavaliere
    • Leandro Dijon
    • Aleksandra Laska
    • Damian Koszelow
    2024 Full text INTERNATIONAL JOURNAL OF HYDROGEN ENERGY

    High grade pellets with basicity index close to 0.5 were directly reduced in pure hydrogen atmosphere. The reduction experiments were performed in the temperature range 800 e1000 C at the pressure of 8 bar. The pellets internal structure was analysed through micro tomography observations in the unreduced and reduced conditions. After reduction, the pellets showed a variation of porosity up to more than 15% with a remarkable change in the pore dimensions and aspect. Given the pores aspect variations, tortuosity strongly varied. This is believed to have large influence on the pellets reduction kinetics depending on the reduction conditions. After reduction, the pellets were re-oxidized in the temperature range 200e700 C for different times. Up to 500 C the weight increase due to oxidation resulted very slow, for higher temperatures the re-oxidation behaviour showed a very remarkable acceleration.

  • Hydroxyl and sulfate radical-based degradation of ciprofloxacin using UV-C and/or Fe2+-catalyzed peroxymonosulfate: Effects of process parameters and toxicity evaluation
    • Jibran Iqbal
    • Noor S. Shah
    • Javed Ali Khan
    • Kifayatullah Khan
    • Muhammad Wakeel
    • Heba Taha M. Abdelghani
    • Zia Ul Haq Khan
    • Grzegorz Boczkaj
    2024 JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY

    Ciprofloxacin (CIP) is a valuable antibiotic and discharged in huge quantities in aquatic environment. Different •OH and SO4•−-based advanced oxidation technologies (AOTs), e.g., Fe2+/PMS, UV-C/PMS, and UV-C/Fe2+/PMS are developed for treatment of CIP. The removal of CIP by Fe2+/PMS, UV-C/PMS and UV-C/Fe2+/PMS was 63, 77, and 87 %, respectively, under identical conditions which showed better performance of UV-C/Fe2+/PMS. The UV-C/Fe2+/PMS also caused high removal of total organic carbon of CIP. This high performance of UV-C/Fe2+/PMS-based AOTs possibly looked due to dual activation of PMS by UV-C and Fe2+. The removal of CIP by the three AOTs was found due to •OH and SO4•− and the later showed high reactivities with CIP, i.e., 2.45 109 and 2.35 109 M−1 s−1, respectively. The study of factors affecting the reactivities and/or yield of •OH and SO4•− diminished CIP degradation efficiency. The change in pH of solution and temperature and doses of Fe2+, PMS, and CIP exhibited significant impacts on the removal of CIP. The addition of inorganic ions showed strong inhibiting effects of NO2–, CO32–, and HCO3– while Cu2+ showed facilitating role. Analysis of degradation of CIP by GC–MS was used to develop proposed pathways. Acute and chronic toxicities of CIP and its products were measured by ECOSAR program and showed the resulting products to be non-toxic.

  • Hyperbaric Storage at Subzero Temperature – the Effect on the Shelf-Life and Selected Quality Characteristics of Raw Pork Sausages
    • Edyta Malinowska-Pańczyk
    • Katarzyna Mazur
    2024 Full text Polish Journal of Food and Nutrition Sciences

    The aim of this study was to determine the microbiological stability and changes occurring in selected physicochemical properties of raw pork sausages during hyperbaric storage at subzero temperature (HS-ST). It was shown that storage at moderate pressures (up to 111 MPa) led to a reduction in microbial populations. After 21 days of storage under these conditions, no microorganisms were detected in the samples. Additionally, the inhibition of thiobarbituric acid reactive substance (TBARS) formation was observed under HS-ST conditions. The negative effect of the storage at 111 MPa/−10℃ was the sausage colour change from pink to grey-pink or grey, visible to the naked eye. Such changes did not occur in the samples stored at 60 MPa/−5℃ for 35 days. The results showed that applying HS-ST at 60 MPa/−5℃ allowed the shelf-life of raw pork sausages to be effectively extended by at least 35 days without visible quality deterioration.

  • Hypericum alpestre extract exhibits in vitro and in vivo anticancer properties by regulating the cellular antioxidant system and metabolic pathway of L‐arginine
    • Mikayel Ginovyan
    • Hayarpi Javrushyan
    • Hasmik Karapetyan
    • Izabela Koss-Mikołajczyk
    • Barbara Kusznierewicz
    • Anna Grigoryan
    • Alina Maloyan
    • Agnieszka Bartoszek
    • Nikolay Avtandilyan
    2024 CELL BIOCHEMISTRY AND FUNCTION

    Conventional treatment methods are not effective enough to fight the rapid increase in cancer cases. The interest is increasing in the investigation of herbal sources for the development of new anticancer therapeutics. This study aims to investigate the antitumor capacity of Hypericum alpestre (H. alpestre) extract in vitro and in vivo, either alone or in combination with the inhibitors of the L‐arginine/polyamine/nitric oxide (NO) pathway, and to characterize its active phytochemicals using advanced chromatographic techniques. Our previous reports suggest beneficial effects of the arginase inhibitor NG‐hydroxy‐nor‐L‐arginine and NO inhibitor NG‐nitro‐Larginine methyl ester in the treatment of breast cancer via downregulation of polyamine and NO synthesis. Here, the antitumor properties of H. alpestre and its combinations were explored in vivo, in a rat model of mammary gland carcinogenesis induced by subcutaneous injection of 7,12‐dimethylbenz[a]anthracene. The study revealed strong antiradical activity of H. alpestre aerial part extract in chemical (DPPH/ABTS) tests. In the in vitro antioxidant activity test, the H. alpestre extract demonstrated pro‐oxidant characteristics in human colorectal (HT29) cells, which were contingent upon the hemostatic condition of the cells. The H. alpestre extract expressed a cytotoxic effect on HT29 and breast cancer (MCF‐7) cells measured by the MTT test. According to comet assay results, H. alpestre extract did not exhibit genotoxic activity nor possessed antigenotoxic properties in HT29 cells. Overall, 233 substances have been identified and annotated in H. alpestre extract using the LC‐Q‐Orbitrap HRMS system. In vivo experiments using rat breast cancer models revealed that the H. alpestre extract activated the antioxidant enzymes in the liver, brain, and tumors. H. alpestre combined with chemotherapeutic agents attenuated cancer‐like histological alterations and showed significant reductions in tumor blood vessel area. Thus, either alone or in combination with Nω‐OH‐nor‐L‐arginine and Nω‐ nitro‐L‐arginine methyl ester, H. alpestre extract exhibits pro‐ and antioxidant, antiangiogenic, and cytotoxic effects.

  • ICT-enabled circular economy: conceptualising the links
    • Ewa Lechman
    • Radosław Ślosarski
    2024

    This chapter sets conceptual backgrounds regarding the potentially emerging causal links between digital technologies and circular economy ideas implementation. We argue that digital technologies may constitute an effective element enabling the transformation from linear to circular and environmentally friendly economic activities. This work draws the general picture at the macro and micro level. The macro perspective shows how individual actions aggregate into global ones that can be demonstrated through, for instance, waste management, resource productivity or, inter alia, statistics. Regarding the micro level, we intended to show how current business models are transforming into circular business models and how companies adopt and use digital technologies to tackle the idea of circular economy and implement it. Lastly, we draw several policy implications.

  • Ideas of the New European Bauhaus (NEB) in architectural education
    • Antoni Taraszkiewicz
    • Karolina Taraszkiewicz
    2024 Full text World Transactions on Engineering and Technology Education

    The New European Bauhaus (NEB) is an interdisciplinary project initiated by the European Commission in 2020 [1], based on three values: sustainability, beauty and community (social inclusion). Its aim is to support the European Green Deal programme [2] by accelerating the transformation of various economic sectors, including construction, to improve the quality of people’s lives and protect the natural environment. Even though the NEB ideas have been known in Europe and around the world for over three years, it turns out that they receive very little attention in contemporary architectural education in some countries. A survey conducted among students in the 4th semester of the first-cycle studies in the Faculty of Architecture at Gdańsk University of Technology, Gdańsk, Poland, indicated that students do not know the NEB ideas and do not try to implement them in their design work. Hence, the need to create an appropriate base - a school in which students are able to directly and tangibly encounter all sustainable spatial, functional, technical and technological solutions according to the values and requirements of modern society.

  • Identification of Determinants of Using Crowdfunding as a Source of Financing the Development of Social Enterprises–the Perspective of Polish Social Entrepreneurs
    • Martyna Wronka-Pośpiech
    • Aldona Frączkiewicz-Wronka
    • Maria Węgrzyn
    • Krzysztof Leja
    2024

    Social enterprises face funding challenges caused, among other things, by investors focusing too much on risk and return. As traditional capital markets do not meet the needs of social entrepreneurs, crowdfunding can be an alternative way to raise funds for the development of their business. In this context, crowd-funding has not been sufficiently researched, and its growing importance in business finance makes it worth understanding its impact on social enterprises. Therefore, this paper helps to fill this gap in the literature by analysing social entrepreneurs’ use of alternative forms of finance such as crowdfunding. The observation of social enterprise activities in Poland, which has been carried out systematically for several years, justifies the thesis that this phenomenon as a practical activity is relatively new and research is fragmentary and rather than in-depth. Hence the idea to address this very issue in this paper. Therefore, our study collects qualitative data from 21 social entrepreneurs to find out the reasons that facilitate or hinder its use by social enterprises.

  • Identification of Public Service Logic (PSL) and Public Service Motivation (PSM) elements in Open Government Data (OGD) initiatives
    • Fredrick Ishengoma
    • Shao Deo
    • Raphael Gouvêa
    • Guilherme Costa Wiedenhöft
    • Ricardo Matheus
    • Charalampos Harris Alexopoulos
    • Nina Rizun
    • Stuti Saxena
    2024 Electronic Journal of Information Systems in Developing Countries

    While previous research on Open Government Data (OGD) has primarily focused on reuse and adoption, this study aims to explore the implications of the Public Service Logic (PSL) and Public Service Motivation (PSM) dimensions in the context of OGD initiatives. This study is contextualized in Tanzania wherein the OGD initiatives are at an evolving stage. For the present study, the perspectives of the 15 public officials involved in the management of the OGD initiatives are being solicited. Findings underscore the need for furthering the marketing and refurbishing the OGD initiatives' quality alongside the increased involvement of the stakeholders to engage in value co-creation. Furthermore, as a study contextualized in a developing country to understand the involvement of the public personnel in the refurbishment of the OGD initiatives, the study contributes to the extant OGD literature while identifying the OGD publisher-side challenges and strengths in a still-evolving OGD initiative. Finally, with its societal implications in terms of the impact on societal stakeholders' engagement with OGD given the PSL-PSM of the public officials, the study's relevance is also clinched

  • Identyfikacja instrumentu muzycznego z nagrania fonicznego za pomocą sztucznych sieci neuronowych
    • Maciej Blaszke
    2024 Full text

    Celem rozprawy jest zbadanie algorytmów do identyfikacji instrumentów występujących w sygnale polifonicznym z wykorzystaniem sztucznych sieci neuronowych. W części teoretycznej przywołano podstawy przetwarzania sygnałów fonicznych w kontekście ekstrakcji parametrów sygnałów wykorzystywanych w treningu sieci neuronowych. Dodatkowo dokonano analizy rozwoju metod uczenia maszynowego z uwzględnieniem podziału na sieci neuronowe pierwszej, drugiej i trzeciej generacji. Opisano także powszechnie stosowane metody archiwizowania wyników treningu sztucznych sieci neuronowych oraz wystąpień artefaktów. Na podstawie przeglądu literatury zaproponowano tezy rozprawy. W części eksperymentalnej w pierwszej kolejności opisano dostępne i zgromadzone zbiory nagrań instrumentów muzycznych oraz sposób ich przekształcenia do formy zbioru treningowego, walidacyjnego i ewaluacyjnego. Przeprowadzono eksperymenty sprawdzające zasadność zaproponowanej koncepcji na mniejszym zbiorze danych. Na tym etapie zaimplementowano modele sieci neuronowych odpowiadające stanowi wiedzy w kontekście identyfikacji instrumentów muzycznych w celu porównania wyników z zaproponowanym modelami. Bazując na wstępnych wynikach, zaproponowano i przeprowadzono rozszerzone eksperymenty na zbiorze danych treningowych zawierających 13 instrumentów muzycznych, w tym rzadko występujących w typowym instrumentarium oraz w bazach muzycznych. W badaniach tych zostały wykorzystane modele sieci neuronowych drugiej oraz trzeciej (sieci impulsowe) generacji, w tym własne propozycje modeli. W końcowej części zawarto analizę uzyskanych wyników oraz omówiono wnioski z niej płynące, służące udowodnieniu tez badawczych. Przedstawiono również najważniejsze osiągnięcia rozprawy oraz kierunki rozwoju badań, mających na celu identyfikację instrumentów muzycznych w sygnale polifonicznym.

  • Imidazole-Based Lithium Salt LiHDI as a Solid Electrolyte Interphase-Stabilising Additive for Lithium-Conducting Electrolytes
    • Marek Broszkiewicz
    • Bartosz Brzozowski
    • Tomasz Trzeciak
    • Aldona Zalewska
    • Jacek Ryl
    • Leszek Niedzicki
    2024 Full text MOLECULES

    Lithium salt LiHDI (lithium 4,5-dicyano-2-(n-heptafluoropropyl)imidazolide) is proposed as a solid electrolyte interphase-stabilising additive for lithium-ion batteries, which can be added in a smaller amount than fluoroethylene carbonate (FEC) and vinylene carbonate (VC) additives. Electrolytes containing either lithium 4,5-dicyano-2-(trifluoromethyl)imidazolide (LiTDI) or battery-standard LiPF6 were tested with various amounts of LiHDI additive. Chemical stability in the presence of water and the thermal stability of LiHDI are on par with LiTDI. LiHDI additive does not negatively affect the properties of electrolytes. Conductivity measurements of solutions, galvanostatic cycling of graphite-LiFePO4 cells at room temperature, cells’ cycling at 60 °C, internal cell resistance monitoring during cycling, and XPS analysis of electrodes’ surfaces after cycling have been performed. LiHDI, unlike the FEC-VC mixture, does not negatively affect the properties of the electrolyte. Cycling showed improved capacity retention with LiHDI additive with both graphite and LiFePO4 as capacity-limiting electrodes over samples without additives. At elevated temperatures, samples with LiHDI exhibited better capacity retention during cycling than those with FEC-VC. Internal cell resistance can be correlated with capacity retention. XPS results show changes in the composition of SEI depending on the composition of the electrolyte and the duration of cycling.